When you save the mission it should be in /Documents and Settings/User/My documents/Take On Helicopters Other Profiles/<profile_name>/missions/<mission_name>/<mission_name>.sqm You can also save it directly to /Program Files/Bohemia Interactive/Take On Helicopters/missions/ from mission editor. During saving pick "Export to single player missions". Then, there will be <mission_name>.<map_name>.pbo file.